Abstract Benign prostate hyperplasia (BPH) is a chronic and highly prevalent medical condition in aging men. Approximately 55% of men aged 60-70 years are affected by BPH and associated lower urinary tract symptoms (LUTS), a progressive and chronic medical condition that drastically impairs quality of life. While first-line drug therapies successfully impede further enlargement of the prostate gland, they only provide modest symptom relief and are associated with a prominent side effect profile that directly impacts quality of life. As a result, surgical intervention is necessary in 30% of all men afflicted with BPH, making it one of the most common procedures among elderly men with estimated annual direct costs of $1.1B in the U.S. alone. Transurethral resection of the prostate (TURP) is effective for improving LUTS, but the procedure is invasive and has a prominent side-effect profile. While less invasive surgical techniques for BPH have reduced the complications associated with TURP, these techniques have limited efficacy and/or poor long-term durability. Even the Prostatic Urethral Lift (PUL) procedure, a promising new therapy, has an early indication of poor long-term LUTS symptom relief. To address the need for a minimally invasive approach that has robust long-term effectiveness and minimal comorbidities, TheraNova has developed the TUCT Catheter, a transurethral cryotherapy (TUCT) catheter system for BPH treatment. The TUCT Catheter is comprised of a urinary catheter/balloon system that provides uniform delivery of cryotherapy to both lateral lobes of the prostate through a single approach and without the need for repositioning. The goals of this Phase I proposal are to optimize the TUCT Catheter system parameters for cryotherapy treatment and assess safety and effectiveness in a pilot preclinical study. In Specific Aim 1, we will test the TUCT Catheter in a benchtop model to optimize system parameters for achieving the desired cryotherapy dose. The optimized system will be used in Specific Aim 2 to determine the effectiveness of the TUCT Catheter cryotherapy treatment, relative to a sham-control treatment, to induce cell death of prostate cells in an animal model. We will also evaluate urethral damage and bladder function one week after treatment. The data obtained through this proposal will be used to demonstrate proof-of-concept for this novel cryotherapeutic technology for BPH. These data will also be used to support a Phase II submission, which will include a pivotal pre-clinical study and a pilot clinical study to determine clinical effectiveness of the TUCT Catheter for the treatment of BPH.